* storagenode/storagenodedb: Migrate to separate dbs
* storagenode/storagenodedb: Add migration to drop versions tables
* Put drop table statements into a transaction.
* Fix CI errors.
* Fix CI errors.
* Changes requested from PR feedback.
* storagenode/storagenodedb: fix tx commit
* internal/dbutil/sqliteutil: Fix error handling, ensure connections are closed
* internal/dbutil/sqliteutil: Separate function to handle conn
* internal/dbutil/sqliteutil: Fix names
- Drops some unused indexes
- Applies a computed index to timestamp columns
- Applies a partial index for expired pieces
- Uses BETWEEN to avoid some datetime calls
- Filters expired piece search by those that aren't NULL
